Much thought about humility, and how to instill it, is wrong. True humility comes from a realization that other people have valuable qualities, not from the belief that one does not have valuable qualities himself. When defined and practiced this way, humility becomes a virtue that creates interactions among people based on mutual respect.
What we see in many situations is a totally different approach to the matter. People think that through violence and abuse they will make other people be humble. That does not create humble people, that creates broken people. This results in vast and unneeded loss as well as vast violation of people's rights.
Real humility therefore does not come from abuse. If anything, the abusive practices bring on a revolt against themselves and everything of which they are a part, resulting in a creation of rebels. Whereas true humility does not do any such thing. It simply brings on a recognition that there are other people with worthwhile qualities; and that results in more intelligent, more respectful, and more wholesome social interactions and ways of life.
Thinking oneself to be trash is not true humility; it is false humility. A person who thinks that is likely to also become abusive to others, which a genuinely humble person will never do. So when Luther refers to humanity as "maggots" and "filth," he is not being humble; he is being an abuser. We see a lot of similar conduct among many practicioners of Christianity and Islam, as well as among many people who are not religious.
If you really want to know what humility actually means, it is best to learn it from the Buddhists. I went to see a very famous Buddhist teacher speak, and he was not abusive at all. He was speaking convincingly of a better way to be and he showed it in his actions. He was respectful to his students while making a very strong case for better conduct, which conduct he demonstrated in his own behavior. Here was someone who was not a hypocrite and who was not an abuser. Here was someone who knew something that people need to know and was willing to share it with them.
Genuine humility means respect, compassion and tolerance for others. It does not mean thinking poorly of oneself or thinking that the next person is better. It does not mean having no positive regard for oneself. It means having positive regard for others also, and it means recognizing the virtues in other people.
For a long time I was against humility because of how it was taught. I realize now that the problem is not with humility but with false humility and abusive practices that are used to bring it about. With genuine humility, world actually does stand to be a better place. And this means that it has to be taught right - by explaining what true humility actually means and making a case for a better world we stand to have if people choose to practice it.